On a night when Randy Johnson was human, on a night when an unknown rookie named Marcus Thames inscribed his name in Yankees history, on a night when a slight chill in the air brought back some post-season vibes to Yankee Stadium, reliable and at times forgotten Shane Spencer made the night his own.

Spencer delivered a grand slam in the bottom of the eighth inning, producing yet another magic moment against the Diamondbacks at Yankee Stadium. Just like last year’s World Series, when the Yankees won three straight home games in dramatic fashion, a relief pitcher – this time Bret Prinz – was victimized as the Yankees thrilled a crowd of 45,698 with a 7-5 victory.

What a night it was, starting with a two-run home run by Thames on the very first pitch of his very first major-league at-bat, off the Big Unit, no less, continuing with some gutsy relief work from Mike Stanton, and ending with the game-winning blast from Spencer, who as recently as last week was informed he was being benched.

“Definitely a little bit more than just a game,” Stanton said. “Almost like a playoff atmosphere. This is why we have interleague play.”

This was reminiscent of Games 3, 4 and 5 of last year’s World Series – Yankee fans would like to forget what happened in the final two games in Arizona – and should once again serve as a reminder to Arizona manager Bob Brenly: Stop using your bullpen to close games in Yankee Stadium. It doesn’t work.

The Yankees trailed 4-3 and chased Johnson – who was not his usual dominating self in tossing 134 pitches – with two outs in the eighth and runners on second and third. Here’s where Brenly’s strategy went up in smoke. He opted not to use his closer, Byung-Hyun Kim – who was victimized twice in the World Series – because Kim had pitched in the last five games.

Bad move. Brenly needed a key out in the eighth and to get it he called for the right-handed Prinz, a 24-year old who had allowed eight walks in 82/3 innings. Brenly instructed Prinz to intentionally walk pinch-hitter Robin Ventura to load the bases, putting a world of pressure on the reliever.

“It seems like when they walk a guy to get to you it gets you pumped up,” said Spencer, the next batter. “You want to be in those situations.”

Spencer, who hit the ball hard all night and had a double and single off Johnson, came up and Prinz fell behind 3-0. He got two strikes and then, on a high and tight fastball that should have been ball four, Spencer launched his first grand slam in four years into the bullpen in left, setting off a delirious celebration.

The crowd called for Spencer and he obliged with a curtain call, pumping his right fist into the air.

“You can hear ’em screaming in your ear, people pushing you up, it’s a great feeling,” Spencer said.

Stanton, filling in for closer Marino Rivera, who was placed on the DL yesterday, created and then wiggled out of a based loaded situation in the eighth. He pitched the final two innings to pick up the victory. Johnson took the loss and is now 9-2.

Spencer got the most important hit, but the most astounding came from Thames, a 25-year old rookie outfielder recalled from Columbus earlier in the day and inserted into the starting lineup. Thames, on the first pitch he saw, became only the second player in Yankees history (covering 100 years) to hit a home run in his first at-bat and the first ever to do so at Yankee Stadium. Back in 1966, John Miller in his only season with the Yanks hit a homer in his first big-league at-bat. That came at Boston’s Fenway Park, though. No one had ever made so grand a debut at the fabled ballpark in the Bronx. Until now.

“I’m not going to tell you I wasn’t nervous,” Thames said. “When I hit it I was like, ‘Go ball, go.’ “